A Survey of Congestion Control in Vehicular Ad-Hoc Networks(VANET)

In recent years, a new technology known as the vehicular ad hoc network (VANET) has attracted a lot of attentions in an effort to provide efficient traffic management and reduce car accidents. For the purpose of the safety applications, vehicles must be capable of transmitting awareness messages throughout the neighborhood with extremely low latency and packet loss. With more vehicles on the road, the dynamic scenario may require for a high message exchange rate, which might easily result in radio channel congestion and a degradation of safety-critical services. The Decentralized Congestion Control (DCC) approach was created by the ETSI in order to alleviate channel congestion. The performance of this strategy is variable depending on the algorithm that is used (i.e., message rate, transmit power, and data rate). The primary objective of a congestion management approach is to enhance the performance of VANET communication channels for safety applications. This objective is to be accomplished while simultaneously reducing latency, jitter, packet loss, and the number of retransmissions. According to the survey information presented in this article, the DCC standardization attempts need to be reexamined. In order to make an informed comparison of the different methods, we identify the important qualities and performance criteria.